Letter
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Predictions for feed-down enhancements at the $Λ_{c} \bar{D}$ and $Λ_{c} {\bar{D}}^{*}$ thresholds via the triangle and box singularities

Ming-Xiao Duan ^1,*, Lin Qiu ^1,2, Xi-Zhe Ling ¹, and Qiang Zhao ^1,2,†

¹Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
²University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China

^*duanmx@ihep.ac.cn
^†zhaoq@ihep.ac.cn

Phys. Rev. D 109, L031507 – Published 29 February, 2024

DOI: https://doi.org/10.1103/PhysRevD.109.L031507

Abstract

We demonstrate that triangle singularity (TS) and box singularity (BS) mechanisms can produce unique narrow enhancements at the $Λ_{c} \bar{D}$ and $Λ_{c} {\bar{D}}^{*}$ thresholds in the invariant mass spectra of $J / ψ p$ and $J / ψ p π$ , respectively. Taking into account that such mechanisms only depend on the initial $Σ_{c}^{(*)} {\bar{D}}^{(*)}$ interactions near threshold within the TS or BS kinematic regimes, the $Λ_{c} \bar{D}$ and $Λ_{c} {\bar{D}}^{*}$ threshold enhancements can also acquire contributions from both the heavier pentaquark decays and the $Σ_{c}^{(*)} {\bar{D}}^{(*)}$ scatterings of the continuum as a feed-down phenomenon. A search for these structures in the $J / ψ p$ and $J / ψ p π$ spectra in both exclusive and semi-inclusive processes will provide a crucial evidence for the hadronic molecule nature of these observed pentaquarks and clarify the role played by the TS and BS in the near-threshold dynamics.

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References (48)

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Phys. Rev. D 109, L031507– Published 29 February, 2024

Vol. 109, Iss. 3 — 1 February 2024

Received 3 April 2023
Revised 20 October 2023
Accepted 29 January 2024

DOI: https://doi.org/10.1103/PhysRevD.109.L031507

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP³.

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Predictions for feed-down enhancements at the $Λ_{c} \bar{D}$ and $Λ_{c} {\bar{D}}^{*}$ thresholds via the triangle and box singularities

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Predictions for feed-down enhancements at the ΛcD¯ and ΛcD¯* thresholds via the triangle and box singularities

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Physics Subject Headings (PhySH)

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References (48)

Predictions for feed-down enhancements at the $Λ_{c} \bar{D}$ and $Λ_{c} {\bar{D}}^{*}$ thresholds via the triangle and box singularities